Process of producing 1-phenyl-benzanthrone compounds



' 250 C. an intramolecular condensation takes Patented Mar. 1930 5 UNITED STATES PATENT oF mF-j WILLY TRAUTNER, BER-THOLD STEIN, AND ROBERT BERLINER, OF ELIBERFELD, GER- MANY, ASSIGNORS TO GENERAL ANILINE WORKS, INC., OF NEW YORK, N. Y., A

CORPORATION OF DELAWARE PROCESS OI PRODUOJ ING I- PHENYL-BENZAN THRONE COMPOUNDS No Drawing. 'Applieatioaflled July 11, 1927, Seria1 No.'205,030, and in Germany November 23, 1925.

Our invention provides fora novel and convenient method of making l-phenyl-benzanthrone compounds.

We have shown in ounce-pending application Serial No. 135,984 filed on even date, that cinnamic aldehyde compounds condense in nonalkaline medium with anthrone -compounds to form cinnamylidene-anthrones of the general formula? date, that by heating these cinnamylideneanthrone compounds to temperatures of about place with formation of novel l-phenyl-benzanlthrone compounds ofthe' probable formu a:

which are usually yellow colored, crystalline substances, dissolving in concentrated sulfuric acid with characteristic, reddish colors.

We have now foundthat the l-phenyl-benzanthrone compounds can be obtained direct ly from anthrone'and cinnamic aldehyde compounds. To this effect mixtures of the anthrone compound and cinnamic aldehyde are slowly heated to temperatures of about 200 300 (3., the cinnamylidene-anthrones are most likely formed as intermediate compounds and condense under these conditionsto the corresponding l-phenyl-benzanthrone compounds. It is in. this procedure also of parts cinnamic aldehyde are heated to 120, C. until a clear solution is obtained. 0.12

advantage in-certain instances to add to the reaction mixture an acidic condensing agent, or to perform the reaction in a high boiling solvent. As such acidic condensing agents which were found particularly useful we might mention phosphorous oxychloridei zinc chloride, acetic anhydrid, etc. The 1- phenyl-benzanthrone compounds obtained in this manner are substantially identical with those obtained by heating the isolated cinnamylidene-anthrones.

The following examples will further illustrate our invention, the parts being by weight:

Emample 1.19 parts anthrone and 13 parts phosphorous-oxychloride are now added to this solution and the temperature gradually increased to 300 C.; the reaction is interrupted after no more intermediate cinnamylidene-anthrone can be detected in the melt. The 1-phenyl-benzanthrone formed is isolated from the melt in the usual manner.. It is obtained after purification as yelthrone obtainedin Example 1 of our application' Serial No. 135,989 of even date. The

yield is about 30-35 of theory. 0

Example .?.9.7 parts of anthrone and 7 parts of cinnamic aldehyde are heated to the boiling point with 3.5 parts benzamide in such manner that the water formed during the reaction is not returned to the reaction. The reaction is finished after about one hours heating. The cold melt is then run into and dried. 'It is identical with the product The yield is about obtained in Example 1.

I 30-35% of theory.

stron In place of benzamide another high-boiling solvent, for instance, alpha-chloronaphthalene may be used in the foregoing example. 1

'Ewample 3.5.2 parts alpha-hydroxy-anthrone, 3.5 parts cinnamic aldehyde and 0.5 part zinc chloride are gradually heated, whilst stirring, to about 280 C. The reaction is interrupted as soon as a sample of the melt dissolves in concentrated sulfuric acid with a reddish-orange color, showing fluorescence. The melt is then stirred up withmethanol whereby it solidifies. It is then crystallized from pyridine and yellow needles of 1-phenyl-alpha-hydroxy-benzanthrone are obtained.

' .E'wample 4.A suspension of 19 parts anth'rone, 14 parts cinnamic aldehyde, 2 parts potassium acetate and 10 parts acetic anhydrid are heated in an open vessel until a. temperature of about 290 C. is obtained.

The melt is then stirred up with 150 parts hot alcohol, filtered oil cold, the residue-..

boiledup with diluted aqueous'alcohol and g the solidified resinous product rubbed on with adetone. Yellow needles of l-phenyl-benzanthrone are so obtained with a yield of about 30%.

Example 5.A'mixture of 2.8 parts betachloro-anthrone, 1.8 parts cinnamic aldehyde and 1.5 parts a-chloro-naphthalene are slowly heated, a little phosphorous oxychloride is added drop action mass is brought to boiling temperature. The reaction is allowed to cool as soon 'as a sample dissolves in concentrated sulbenzanthrone compounds which consists in heating the mixture of an anthrone combenzanthrone compounds which consists in heating to boiling the mixture. of an anthrone compound, cinnamic aldehyde and alpha-chloro-naphthalene.

3. The process of producing 1-phenyl-.

benzanthrone which consists in heatin the mixture of anthrone and cinnamic alde yde to a temperature of about.200300 (3., in the presence of a high boiling solvent.

.4. The process of producing -1-phenyl benzanthrone which consists in heating to boiling the mixture of 'anthrone, cinnamic aldehyde and alpha-chloro-naphthalene.

- In testimony whereof we have hereunto set our hands.

- .WILLY TRAUTNER.

BERTHOLD STEIN. .ROBERT BERLINER.

by drop and finally the rea I furic acid with the bluish-red, fluorescent color characteristic for the l-phenyl-betachloro-benzanthrone. The so 'obtained dark resinous product is rubbed on with methanofl, it solidifies after some standing. After extracting it with acetone light yellow needles of l-phenyl-beta-chloro-benzanthrone.are obtained with a yield of about 10-20% of theory. 1

Instead of the above mentioned high boiling solvent benzamide or other solvents of this kind can also be used, for instance betachloro-naphthalene, para-phenetidine, etc., that is, generally such solvents which possess at least a boiling point of about 200.

This application contains subject matter in common with our co-pending application SenNo. 135,990, filed Sept. 16,1926, and is to be considered as a continuation in part of said co-pending application.

We claim:

1. The process of producing l-phenyl- 

